Power supply system with secondary control circuitry providing power-based feedback

Abstract

According to one example embodiment, a power-supply system describing a bi-directional flyback topology includes two flyback converters working in opposite directions. Current flowing from a power supply unit to an apparatus is converted from a mains input in the power supply unit to a rectified output current fed to the apparatus via a two-lead cable. In the opposite direction, a secondary control circuit, situated in the apparatus, including a secondary switch causes excess current to be fed back to the power-supply unit where primary control circuitry reacts to stabilize the current fed to the apparatus. The primary control circuitry serves to minimize the amount of energy received from the feedback. The excess current in the apparatus is determined by monitoring the voltage and the current in the apparatus is load. If the measured parameters are too high, transfer of more energy back to the power-supply unit will be performed.

What is claimed is:  
     
       1. Power supply system including a power supply unit and an apparatus, said power supply unit comprising primary control circuitry arranged to control the energy flow to the apparatus via a two-lead cable, characterized in that the system further comprises secondary control circuitry located in the apparatus, said secondary control circuitry being arranged to monitor usage of energy received from the power supply unit and feedback excess energy to the power supply unit via the two-lead cable. 
     
     
       2. Power supply system comprising: 
       a power supply unit and an apparatus, said power supply unit including primary control circuitry arranged to control the energy flow to the apparatus via a two-lead cable; and  
       secondary control circuitry located in the apparatus and being arranged to monitor usage of energy received from the power supply unit and to feed back excess energy to the power supply unit via the two-lead cable, the secondary control circuitry including a switch acting as a synchronous rectifier feeding back current to the power supply unit.  
     
     
       3. Power supply system according to  claim 2 , wherein the switch is in the form of a field effect transistor. 
     
     
       4. Power supply unit arranged to supply electric energy to an apparatus, said power supply unit comprising primary control circuitry arranged to control the energy flow to the apparatus via a two-lead cable, characterized in that the primary control circuitry is arranged to receive feedback energy via the two-lead cable from the apparatus and control the energy flow to the apparatus in response to the feedback energy. 
     
     
       5. An apparatus arranged to receive energy from a power supply unit via a two-lead cable, characterized in that the apparatus comprises secondary control circuitry, said secondary control circuitry being arranged to monitor usage of energy received from the power supply unit and feedback excess energy to the power supply unit via the two-lead cable. 
     
     
       6. An apparatus arranged to receive energy from a power supply unit via a two-lead cable, wherein the apparatus comprises secondary control circuitry, said secondary control circuitry being arranged to monitor usage of energy received from the power supply unit and feedback excess energy to the power supply unit via the two-lead cable and including a switch acting as a synchronous rectifier feeding back current to the power supply unit. 
     
     
       7. An apparatus according to  claim 6 , wherein the switch is in the form of a field effect transistor. 
     
     
       8. A power supply system comprising: 
       a power supply unit and an apparatus, said power supply unit including primary control circuitry arranged to control the energy flow to the apparatus via a multi-lead cable, and  
       secondary control circuitry located in the apparatus, said secondary control circuitry including a switch and being arranged to monitor usage of energy received from the power supply unit and in response to the monitored usage of energy, controlling the switch to provide feedback current to the power supply unit via the multi-lead cable.  
     
     
       9. The power supply system of  claim 8 , wherein the feedback current is determined by the secondary control circuitry to be excess current. 
     
     
       10. The power supply system of  claim 8 , wherein the switch includes a field effect transistor.